Congress yesterday authorized an additional $70 billion in emergency funds to pay for the wars in Iraq and Afghanistan through early next year, including nearly $24 billion for the Army and Marine Corps to repair and replace worn-out equipment.

The new funding provides more than $2 billion for the military's efforts to defeat the road bombs, or "improvised explosive devices," that are the leading cause of deaths among U.S. troops in Iraq.

Senate and House conferees also agreed yesterday on $463 billion in overall defense spending for fiscal 2007, a 3.6 percent increase over 2006. To ease the strain on U.S. ground forces, the conference report called for an increase of 30,000 soldiers and 5,000 Marines in 2007, with additional increases authorized through 2009.

The new funding brings to $507 billion the total amount authorized by Congress for the wars in Iraq and Afghanistan, as well as for extra security for military bases and embassies, since the Sept. 11, 2001, terrorist attacks.

Rising sectarian and insurgent violence is delaying troop cuts until well into next year, and U.S. commanders are increasingly asserting that military power alone is not sufficient to stabilize Iraq.

Yesterday, one U.S. commander in Iraq's volatile Anbar province said the job of American forces in his region is not to defeat the insurgency but to drive the violence down to a point at which it can be handled by Iraqi forces.

"Who knows how long this [insurgency] is going to actually last?" said Army Col. Sean MacFarland, who oversees thousands of U.S. and Iraqi troops fighting in Anbar's troubled capital, Ramadi. "But if we get the level of violence down to a point where the Iraqi security forces are more than capable of dealing with it, the insurgency's days will eventually come to an end. And they'll come to an end at the hands of the Iraqis," he said in a videoconference with reporters.

There are about 142,000 U.S. troops in Iraq and more than 20,000 in Afghanistan, and military officials say those levels will be necessary through next spring. Earlier this year, commanders had thought that those numbers would be lower by several thousand by now.

The higher-than-anticipated troop levels are further straining U.S. ground forces, as the Pentagon has had to keep thousands of soldiers in Iraq beyond the standard year-long tour. This week, the Pentagon extended for more than six weeks the tours of nearly 4,000 soldiers in MacFarland's unit, the 1st Brigade of the 1st Armored Division.

The extension will allow an incoming brigade from the Army's 3rd Infantry Division to have a full year at home before deploying back to Iraq for the third time.

MacFarland said attacks have decreased 25 percent in Ramadi recently, falling from about 20 to about 15 a day, as local tribes have thrown their support behind Iraqi police recruiting efforts. However, he declined to say what impact this decline in attacks was having on U.S. troop casualties in Ramadi, where dozens of soldiers and Marines have died since the beginning of summer.

Senior Pentagon officials have stated emphatically that the U.S. military alone cannot win the war in Iraq, and that political and economic progress is vital to success there. In Anbar province, for example, a Marine intelligence report concluded last month that U.S. forces there faced a military stalemate as insurgents took advantage of weaknesses in the local government and economy. MacFarland acknowledged such problems in Ramadi, where there is no mayor or effective municipal council.

Separately, a senior Pentagon official faulted the U.S. effort in Iraq yesterday, saying that authorities are "struggling" to coordinate various projects and operations there.

"We don't sufficiently have unity of effort yet," said Eric S. Edelman, the undersecretary of defense for policy. Speaking at a State Department conference on how the U.S. government should better conduct counterinsurgency campaigns, he added that he believes it would "take an ongoing adaptive effort" to do better. Specifically, he said, he would like to see more coordination of reconstruction work with military operations.

After Edelman spoke, Meghan O'Sullivan, the deputy national security adviser for Iraqi affairs, stood to say that "the White House sees this as a conference of consequence. We really are in need of new tools."

Some experts on counterinsurgency have criticized the U.S. effort in Iraq for violating the military principle of unity of command, which posits that one person should be in charge of any overall effort. The U.S. presence in Iraq has always been divided, with separate chains of command for the military and for civilians.

Officials from the Pentagon and the State Department said after the Edelman speech that they were not aware of any plans to restructure the U.S. presence in Iraq to create a unified chain of command for the military and civilians.